I read the stick thread about parallax but I'm still a little confused.

While i only have 100-200 yard at my home to work with...

Do i set the Parallax, for every range that I'm shooting? or can i set it on 1000 and leave it there

I seen a video from last years NRA champ, that you can leave a small black circle in the scope and make sure its even on all sides, thus making sure you are true on the scope, if I do this do i still need to adjust the parallax

First off you should set it for every range . However if you are shooting around the hundred then the 100 setting is OK but if you get closer to 200 then the 200 setting should be better . I say should because there is no guarantee that the scope will correct exactly right for your eyes at the ocular focus setting that you need to see the cross hair sharply .
So a good thing to do is test the scope at 100 measured yards on a target.
set the scope for 100 yards parallax correction.
get the normal sight picture , then move your head about side to side up and down a small amount behind the scope . If the cross hair stays on the same target position all the time it's correct for you at that distance . The whole image may move about a bit but the cross hair point of aim should stay locked to the same place on the target .
If it does not and the cross hair wanders about the target then the 100 yard setting is not correct for you at 100 yards range . Play around with the setting each side of the 100 yard marking and find the place where the cross hair is locked to the target and that is the correct place for your eyes at 100 yards.
You can do one of two things , do it at different ranges and remark the scope parallax knob or bell to the correct positions for your eyes or just do the head move thing to zero in on the right correction before a shot using the settings as a rough starting guide . For quick snap shots or running shots the head move thing is impractical and so is mucking about with the parallax to some extent so I do both . I test and remark some of my my scopes and I also do the head move thing to check for slow bi=pod shooting . However when I think moving game is likely , I select a setting say 150 yards and stick with that . Hope that helps .

If the parallax is not tuned right, it can really mess up your point of impact. I tried a Minox scope a 3-15 that was quite expensive but had no adjustable parallax. With a rifle that I knew could shoot 0.5moa, the best I got out of it was 2.5 moa at 100 yards (the distance most non adjustable scopes are supposedly set for). I replaced the Minox with my Nikon Monarch 2 3-12x42 and shot 0.5 moa again. The Minox went back and was replaced with a Vortex Viper PST.

You need to test your scope at known ranges to see if the scale is off. If the parallax is not adjusted correctly the reticle will move on the target when you move your eye but not the rifle. All the adjustment is doing is making the image/target plane coplanar with the reticle plane. That way, if you move your eye, the reticle does not move relative to the target.

Perfect eye placement is just another thing to worry about (and screw up) in the second you have to take a shot. Get to know your parallax adjustment and then setting it is second nature once you have ranged an animal, or pre-set it based on what you are expecting to go down.

If you then need to adjust it, do so, else it may already be set up fine.

You can also get an idea of how close you need to be dialed in at different ranges. A tiny bit off is just a tiny bit off but of course at long range everything matters. At 100-200 yards you just have to be close.

Perfect eye placement is just another thing to worry about (and screw up) in the second you have to take a shot. Get to know your parallax adjustment and then setting it is second nature once you have ranged an animal, or pre-set it based on what you are expecting to go down.

If you then need to adjust it, do so, else it may already be set up fine.

You can also get an idea of how close you need to be dialed in at different ranges. A tiny bit off is just a tiny bit off but of course at long range everything matters. At 100-200 yards you just have to be close.

okay thanks, that clear it up for me, they are both different and necessary steps for an accurate shot, specially over 200 yards

That person may be a champion shooter but she knows little about scopes .
If you push the scope too far forward and create the big black ring you will loose field of view , she is a peep sight target shooter and knows jack about hunting I suspect. It is true that if you can place your eye in exactly the same place each time parallax will be minimised but that's the problem we can't , even with the perfect stock fitting because we shoot from all different positions etc.
What few people know is that even rotating the eye causes focus and parallax problems so just tipping your head down slightly changes things.
Also even the scope lens it's self may not be perfectly symmetrical and rotating it can cause issues. Set the scopes ocular focus first on a clear sky at mid power .
The best eye relief position is a compromise with variable power scopes . As the power changes the best eye relief position for that power changes ,
So what you do is find an eye relief position in about the middle of the power range and get it so you can see as much sight picture as possible . Then ramp the power back and forth to see it's still OK at lowest and highest power , adjust as necessary . Just jamming the scope forward is rubbish .
The best control for parallax is to adjust for it at the specific range and that's what the scopes are deigned to do then it don't matter if your head is not in the perfect + and - .001 position but you should still strive to have a good consistant cheek weld .